Lesson Plan

I can see you...can you see me?





Estimated time of lesson plan: 220 minutes


Grade Level: 8-9

Lesson Topic: Light, Mirrors and Lenses

Organization of students learning: groups of 5
Lesson Author: Ana Selby
Date Created: 7/10/2009
Docs: ,
l lesson e-address: http://anaselby.wikispaces.com/Mirrors
video e-address: http://voicethread.com/share/557981/
online resource: http://gbs.glenbrook.k12.il.us/academics/gbssci/phys/Class/refln/u13l1b.html#p4




Learning objectives and assessment:

Objective #1: The students will explore the optical principles of mirrors
Standard: CLE 3237.3.7 Investigate the interaction of light waves.
Assessment: Identify the phenomenon exhibit in each station and complete a handout when rotating through stations.

Objective
#2:TSW Explore the optical principles of mirrors and lenses
Explore the optical principles of mirrors and lenses
Standard:CLE 3237.3.8 Explore the optical principles of mirrors and lenses.
Assessment: Identify the phenomenon exhibit in each station and complete a handout when rotating through stations.

Objective #3: TSW Differentiate among elements of the engineering
design cycle: design constraints, model building, testing, evaluating,
modifying, and retesting.
CLE 3237.T/E.2 Differentiate among elements of the engineering
design cycle: design constraints, model building, testing, evaluating,
modifying, and retesting.
Assessment: building a periscope

Objective #4: TSW Explain the relationship between the properties of a
material and the use of the material in the application of a technology
CLE 3237.T/E.3 Explain the relationship between the properties of a
material and the use of the material in the application of a technology.
Assessment: Explaining their finding
Objective #5: TSW Apply the engineering design process to construct a
prototype that meets developmentally appropriate specifications.
Standard:93237.T/E.2 Apply the engineering design process to construct a
prototype that meets developmentally appropriate specifications.
Assessment: building a model of a periscope

Objective #7: TSW Explore how the unintended consequences of new
technologies can impact human and non-human communities.
Standard:93237.T/E.3 Explore how the unintended consequences of new
technologies can impact human and non-human communities.
Assessment: the students discuss in a round table the ups and downs of their periscope

Objective #8:TSW Present research on current engineering technologies that
contribute to improvements in our daily lives.
Standard:
93237.T/E.4 Present research on current engineering technologies that
contribute to improvements in our daily lives.
Assessment: Present results in a round table

Objective #9: TSW Design a series of multi-view drawings that can be used
by other students to construct an adaptive design and test its
effectiveness.
Standard:93237.T/E.5 Design a series of multi-view drawings that can be used
by other students to construct an adaptive design and test its
effectiveness.
Assessment: Present design of a periscope

Introduction(Set). (10 min) Present the video clip to the students (or do the demo in the classroom). Ask the students to make hypothesis based on their observations. Ask the students what could be affecting (influencing) the results. Tell the students that after the lab they will have a better explanation. Show the second part of the video after the lab.


Lecture the students using an online resource. Prepare the students for rotation and explain how it will be done. Allow 7 minutes in each station. Give to each group 5 handouts in exploring light (one for each station).

The Law of Reflection

Light is known to behave in a very predictable manner. If a ray of light could be observed approaching and reflecting off of a flat mirror, then the behavior of the light as it reflects would follow a predictable law known as the law of reflection. The diagram below illustrates the law of reflection.
external image u13l1c1.gif
In the diagram, the ray of light approaching the mirror is known as the incident ray (labeled I in the diagram). The ray of light which leaves the mirror is known as the reflected ray (labeled R in the diagram). At the point of incidence where the ray strikes the mirror, a line can be drawn perpendicular to the surface of the mirror. This line is known as a normal line (labeled N in the diagram). The normal line divides the angle between the incident ray and the reflected ray into two equal angles. The angle between the incident ray and the normal is known as the angle of incidence. The angle between the reflected ray and the normal is known as the angle of reflection. (These two angles are labeled with the Greek letter "theta" accompanied by a subscript; read as "theta-i" for angle of incidence and "theta-r" for angle of reflection.) The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
external image animn.gif
It is common to observe this law at work in a Physics lab such as the one described in the previous part of Lesson 1. To view an image of a pencil in a mirror, you must sight along a line at the image location. As you sight at the image, light travels to your eye along the path shown in the diagram below. The diagram shows that the light reflects off the mirror in such a manner that the angle of incidence is equal to the angle of reflection.
external image u13l1c2.gif
It just so happens that the light which travels along the line of sight to your eye follows the law of reflection. (The reason for this will be discussed later in Lesson 2). If you were to sight along a line at a different location than the image location, it would be impossible for a ray of light to come from the object, reflect off the mirror according to the law of reflection, and subsequently travel to your eye. Only when you sight at the image, does light from the object reflect off the mirror in accordance with the law of reflection and travel to your eye. This truth is depicted in the diagram below.
external image u13l1c4.gif
For example, in Diagram A above, the eye is sighting along a line at a position above the actual image location. For light from the object to reflect off the mirror and travel to the eye, the light would have to reflect in such a way that the angle of incidence is less than the angle of reflection. In Diagram B above, the eye is sighting along a line at a position below the actual image location. In this case, for light from the object to reflect off the mirror and travel to the eye, the light would have to reflect in such a way that the angle of incidence is more than the angle of reflection. Neither of these cases would follow the law of reflection. In fact, in each case, the image is not seen when sighting along the indicated line of sight. It is because of the law of reflection that an eye must sight at the image location in order to see the image of an object in a mirror.



Instruction/Activities.
1. There will be 5 work stations where the students will find and try a demo on optics. The following Word doc. will be posted in every station.

Workstation A: mirrors and candles
Workstation B; Beaker with water and pine sol, laser
Workstation C: Beaker with a colloid. Laser
Workstation D: Concave mirrors
Workstation F: Concave mirrors
2. The students will have a handout that will help them to match the phenomenon observed with the right definition.

3. Students will work in group of a maximum of 5 members.
4. Students report and justify their findings

Assignment.
Students will build a periscope with materials provided in the classroom. Starting with the design on paper of their model.
Use the following link is your students seem to need more help: http://www.onnetworks.com/videos/make-it-awesome/make-a-periscope

Closure. We will have a A round table where students will expose their limitations and they could overcome those. How team work made the job simple or more difficult. What can be change if they try to do it again. What they will keep.
Students will discuss science and technology application of mirrors in society.

Extension Activities. Improve their creation for a school contest. (Up to three periscope per class)


Assessment of Student Learning: Matching test.
Modifications for Diverse Learners.